code: def mainloop(duration=1):
      """run the Cocoa eventloop for the specified duration (seconds)"""
  
      _triggered.clear()
      NSApp = _NSApp()
      _stop_after(duration)
      msg(NSApp, n("run"))
      if not _triggered.is_set():
          # app closed without firing callback,
          # probably due to last window being closed.
          # Run the loop manually in this case,
          # since there may be events still to process (ipython/ipython#9734)
          CoreFoundation.CFRunLoopRun()
  
file_path: catboost/contrib/python/ipykernel/py2/ipykernel/_eventloop_macos.py
imports: import ctypes
  import ctypes.util
  from threading import Event
label_desc: Use image node_id 8 for calling a global function with example usage: mainloop(duration) without return types